Chalkline holder



FIG. 1 is a bottom, side and front perspective view of my design for a chalkline holder;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is an elevation view thereof from the same side as in FIG. 1;

FIG. 5 is an elevation view thereof from the side opposite that in FIG. 4;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The portions of the chalkline holder shown in dotted lines do not constitute a part of the claimed design. 

The ornamental design for a chalkline holder, as shown and described. 